Boxers, as a rule, are made of strong stuff.

They’re expected to be tough, agile, and possess a super-human, self-preservation-defying ability to take a punch and keep on going. Streaks of meanness and dashes of crazy are advantages. They’re widely recognized as having the most punishing training regimens in sports.

Patience, on the other hand, is an altogether different virtue.

Rubin “Hurricane” Carter’s patience was thrust upon him. The boxer, who died in his sleep Sunday at home in Toronto, was 76, the Associated Press reported.

The promising prizefighter (27-12-1, 19 knockouts) had to wait 19 years for his freedom after he was wrongfully convicted of three murders 1967 and again in a new trial in 1976. The boxing career which took him all the way to a 1964 middleweight title fight with Joey Giardello (he lost by unanimous decision), was over. Instead, with the help of advocates all over the country and the world, he pounded away at a legal system that locked him away without much evidence.

In 1966, two black men shot and killed three white people in a Paterson, N.J., bar. Witnesses knew the race of the suspects, but could not positively identify Carter and his friend, John Artis. Carter and Artis, who later became his caregiver once he became sick with prostate cancer, were convicted by an all-white jury based on testimony from two thieves who made deals with the prosecuting attorney. The thieves later recanted their stories. Both men were sentenced to life in prison — twice. Artis was released on parole in 1981.

When Carter won his release in 1985, the presiding judge in the case, U.S. District Judge H. Lee Sarokin, wrote that Carter’s prosecution had been “predicated upon an appeal to racism rather than reason, and concealment rather than disclosure.” Sarokin ruled that neither Artis nor Carter had received fair trials and ordered Carter’s release. Prosecutors ultimately dropped the charges. Carter wrote several books about his experiences, including “Eye of the Hurricane: My Path From Darkness to Freedom” and “The Sixteenth Round: From Number 1 Contender to Number 45472.”

Carter found a new life advocating for other innocent men who fell victim a legal system that presumed them guilty. He wrote a column from his deathbed for the New York Daily News, which he used to advocate for the release of two prisoners he believed are innocent. With Win Wahrer, he co-founded the Toronto-based Association in Defence of the Wrongly Convicted. There’s not much difference between the fate suffered by Glenn Ford, Louisiana’s longest-serving death row inmate, recently released after he was exonerated, and Carter. Carter spent 19 years in prison; Ford spent 30. 

“Those who are wrongfully incarcerated lost a champion,” Artis told Reuters. “He dedicated his life to helping the people that need the same kind of assistance that we needed, who have been wrongfully convicted and incarcerated.”

Carter, who became the subject of a 1975 Bob Dylan song and a 1999 movie starring Denzel Washington, rose to the challenge of being recognized as a symbol of racial discrimination in the U.S. justice system and used his spotlight to illuminate the stories of others. “If you’re not a lawyer, or haven’t gone to school to study the law, when it comes to the criminal justice system, you are brain dead,” Carter said to Tavis Smiley in a 2011 interview. “The criminal justice system is not about justice. It is about success. Successful police officers are promoted. Successful prosecuting attorneys become judges. A successful judge goes to a higher court. … A successful judge, Tavis, in our system of jurisprudence, is a careful judge, and not necessarily a wise one.”

He was widely praised for rejecting a life of public bitterness following his release, but he didn’t mince words, either.

“If I find a heaven after this life, I’ll be quite surprised,” he wrote in the Daily News. “In my own years on this planet, though, I lived in hell for the first 49 years, and have been in heaven for the past 28 years. To live in a world where truth matters and justice, however late, really happens, that world would be heaven enough for us all.”